Power-transmission clutch.



No. 872,481. PATENTED DEC. 3, 1907.

C. O. TILLOTSON. POWER TRANSMISSION CLUTCH.

APPLICATION FILED MAY 29, 1907.

I VITNESSES @harle's C fi'llots'on,

[NI/ENTOR.

uniran STATES PATENT OFFICE.

CHARLES c. rrLLo'rsoN', or GLATHE, KANSAS.

rownn-mmsmssrox cmrcn.

To all whom it may concern: v

Be it known that I, CHARLES C. TILLOT- soN, a citizen of the UnitedStates, residing at ()lathe, in the county of Johnson and State ofKansas, have inventeda new and useful Device, of which the following isa specification.

This invention has relation to the power transmission clutch, on whichLetters Patent No, 850981 issued to myselfApr. 23, 1907.

The object of the invention is-to improve the construction of the clutchfor eater simplicity in manufacture and use. his is accomplished byproviding a shifting arrangement and shield for the coil spring of theaforesaid clutch and rigidly connecting the two driving members.

The shiftin device consists of a hollow cylinder slight y longer thanthe said spring,- and having both ends closed with the exception ofcircular oplenings concentric with the cylinder, throug which openingsmay pass the shafts on which the coil spring operates. The device whenin place completely surrounds and incloses the coil spring, protectingit from mechanical injury and preventing the entrance of dirt or foreignmatter. On the inner surfaces of the ends of the hollow cylinder teethare formed, in

- axis at the same time it is such a manner that when the cylinder isturned one way the teeth will slip over the end of the spring, but whenturned the other way a tooth will engage the end of the spring, causingit to expand, until it becomes loose enough to slip on its shaft. Ifforce is applied to the cylinder in the direction of its t given itsrotary motion, it will push the loosened spring longitudinally along theshaft, as well as causing 1t to slip around theshaft.

In the accompanying drawing a side elevation, partly in section, and endelevation of one form of the shifting device. Fig. 2 shows another formof the device with on y one end closed as above described, the other endbeing screwed into a part of the machine to which it is applied. Fig. 3is a plan of a screwdriver, partly in section, showin the device inplace, and Fig. 4 is an externa elevation of the same screwdriver.

The number of any part is the same in all Figure 1 is l the figures.

Fig. 1 shows the device as made of a section of hollow cylinder 1, andtwo end pieces 2, having internal teeth stamped or pressed therein, andattached to part 1 by being Specification of Letters Patent. Applicationfiled Key 29, 1901. Serial Ho. 376.294.

forced on by pressure, or soldered, brazed or sweated on. 'The ends mayalso bescrewed on, or fastened in any rigid manner. One

end may be formed from the main part 1 by stamplng, crim ward into thepart 2 may be formed in casting, or by cutt ng, stamping, or in anyother manner. It may be desirable, in case the teeth are stamped, tomake them on a flat annular disk, and fasten the latter firmly againstthe end of the cylinder with a plain cap.

In 2 the shield 1 inclos'es the coil spring 6, which forms theconnection clutch between shafts 3 and 5. Means for keeping shafts 3 and5 in exact alinement are not shown in this figure, but this object maybe attained by a smaller shaft passing through both, by a, stud screwedinto one and serving as a shaft for the ings beyond the figure shows theing or spinning the end inlimits of the figure. This clutch as appliedto a machine where only single action lsdesired.

Fig. 3 shows a combination of coil s ring clutch and shifting device,where the l atter more completely serves the dual purposes of PatentedDec. 3,1907... I

esired shape. The teeth on other, or by means of bearprotecting theclutch and of shifting it when desired. The bit of the screwdriver is securely fastened to the collar or hollow shaft 3 by a pin 9 passingthrough both. The spring 6, shown in section, embraces 3 and the drivingmember 5, which is retained firmly and revented from turning in thehandle by t e pin 7. When reci rocatin rotary movement is given to theandle. o the screwdriver be ri ht handed) the bit will be turned to theleft, hut will slip in turning to the right, thus acting to draw out ascrew. To adjust the screwdriver for driving screws, hold the handle andbit from turning, and turn the shield 1 to the right, at the same timeforcing it outward away from the handle. In this action oneof the teethat the handle end of the shield engages the end of the spring, looseningit and slipping it over 3 onto 4 and off of 5. Part 4 is reversed at thebit end and fastened, in the handle by means of the same pin 7 as 5 is.There is now no positive connection between 5 and 3, and when the handleis turned shaft 4 will drive 3 to the right, but will slip on turning tothe left, and the screw be driven in. If a left hand coil is used inplace of the right hand one as above descrlbed, the operation of thescrewdriver will be reversed in each case.

(assuming the coil spring to getting the motion transmitted eit timehaving The advantage of a coil spring to cover completely only the twoparts 3 and 4 pr 3 and 5, ovcrQno covering all three arts 1s m ier tothe right or left as desired, while at the same the two driving membersrigidly connected to ether, thus avoiding the necessity of any otherclutchin devices outside of the coil sprin and its shield. This is themain object 0? the invention.

It will be observed that when the coil spring shifted to a positionmidway between the two extremes possible, it will cover all of 3 andpart of 4 and 5, and the/bit will therefore be turned either way thehandle is turned.

Fig. 4 shows the outer shell of part 4- cut away on two sides to makethe shifting device accessible. The latter should be knurled orroughened to facilitate turning.

These improvements may be used to advantage on the coil spring clutchwherever ratehets are now used, including screw drivers, bit braces,lawn mowers, mowing machines, automo iles, on wrenches, die plates andpipe cutters, on clocks, watches and micrometer callipcrs, and manyother common articles. In many of these cases the hollow cylinder mayact principally or solely as a shield, in case shifting the spring isunnecessary, as when action in one direction only is desired. In suchcases the teeth inside the ends of the cylinder may sometimes be disensed with.

Letters Patent No. 850981 IIIVOlVG a cylindrical driven member, twosimilar driving members and a coil spring embracing them. I do not claimthese, but

What I claim as new and desire to secure by Letters Patent is 1. In acoil spring clutch, comprising roack screws, brakes, crank shafts oftion with other length of but two of the same,

tar members and a voluted spring member em racing the aforesaid membersand enga in the same frictionally only, a hollow cylin rical shieldfitting over said rotary members in such manner as to be retained inposition coaxialzwith them,,and injconjunearts completely surroundingand inclosing t ie aforesaid voluted. spring member.

2. A coil spring clutch comprising a rotary driven member, and tworotary driving members a voluted spring member embracing the aioresaidmembers, and engaging the same frictionally only, said springmembercxtending over the driven member and one of the driving members,and a shifting device consisting of a hollow cylinder having its endsflanged inward to fit over the said rotaryinembers, and with inwardlyprojecting teeth formed thereon in such manner as to release the springmember and shift it longitudinally to any desired position on thedriving and driven members.

3. A clutch comprising a trinity of alined rotary members, a volutedspring member embracing the aforesaid members and of such length as toextend along the entire a hollow cylinder inclosing the voluted springmember, and one or more members rigidly connecting the two drivingmembers, and reventing the rotary movement of either w1th respect to theother, all substantially as shown and described herein.

In testimony that I claim the foregoing as my own I have hereto aiiixedmy signature in the presence of two witnesses.

CHAS. C. TILLOTSON. Witnesses:

A. W. LARUE, GEO. S. SHEPHERD.

